Extreme exoplanet has a complex and exotic atmosphere

Artist's impression of WASP-189b, an exoplanet orbiting the star HD 133112 which is one of the hottest stars known to have a planetary system. Bibiana Prinoth - An international team including researchers from the University of Bern and the University of Geneva as well as the National Centre of Competence in Research (NCCR) PlanetS analyzed the atmosphere of one of the most extreme known planets in great detail. The results from this hot, Jupiter-like planet that was first characterized with the help of the CHEOPS space telescope, may help astronomers understand the complexities of many other exoplanets - including Earth-like planets. The atmosphere of Earth is not a uniform envelope but consists of distinct layers that each have characteristic properties. The lowest layer that spans from sea level beyond the highest mountain peaks, for example - the troposphere - contains most of the water vapour and is thus the layer in which most weather phenomena occur. The layer above it - the stratosphere - is the one that contains the famous ozone layer that shields us from the Sun's harmful ultraviolet radiation. In a new study that appeared in the journal Nature Astronomy, an international team of researchers led by the University of Lund show for the first time that the atmosphere of one of the most extreme known planets may have similarly distinct layers as well - albeit with very different characteristics.